Topic 5

Two objects attract each other gravitationally with a force of 2.9x10'1O N when they are 0.65 m apart. Their total mass is 5.0 kg. V PartA Find their individual masses. Express your answers using one decimal place separated by a comma. m Muest Answer Item3 I Review | Constants V PartA What is the magnitude of the acceleration of a speck of clay on the edge of a potter's wheel turning at 44 rpm (revolutions per minute) if the wheel's diameter is 34 cm ? Express your answer to two significant figures and include the appropriate units. m Euest Answer Item 4 4 of 16 Review | Constants On an ice rink, two skaters of equal mass grab hands and spin in a mutual circle once every 2.6 s . Part A If we assume their arms are each 0.80 m long and their individual masses are 63.0 kg , how hard are they pulling on one another? Express your answer to two significant figures and include the appropriate units. HA ? F = Value Units Submit Request AnswerItems IUII 001" -'> Q) Earth FMS A 0 Sun V PartA Find the net force on the Moon (mM 2 735 x 1022kg) due to the gravitational attraction of both the Earth (mE = 5.98 x 1024kg) and the Sun (m3 = 1.99 x 1030kg), assuming they are at right angles to each other ( gure 1). Express your answer to three significant figures and include the apprOpriate units. Part A Find the net force on the Moon (mM = 7.35 x 1022kg) due to the gravitational attraction of both the Earth (ME = 5.98 x 1024kg) and the Sun (ms = 1.99 x 1030kg), assuming they are at right angles to each other ( Figure 1). Express your answer to three significant figures and include the appropriate units. HA ? Fnet = Value Units Submit Request Answer Part B Determine the direction of the net force. Express your answer to three significant figures and include the appropriate units. HA ? 0 = Value Units Submit Request AnswerItem 7 The design of a new road includes a straight stretch that is horizontal and flat but that suddenly dips down a steep hill at 19 0 Figure Item 9 Review | Constants Part A Highway curves are marked with a suggested speed. If this speed is based on what would be safe in wet weather, estimate the radius of curvature for an unbanked curve marked 70 km/h . Use Table 4-2 in the textbook (coefficients of friction). Express your answer to one significant figure and include the appropriate units. ? r= Value Units Submit Request AnswerItem 10 10 of 16 A race car starts from rest in the pit area and accelerates at a uniform rate to a speed of 38 m/s in 15 s , moving on a circular track of radius 500 m. The car's mass is 1000 kg . Part A Assuming constant tangential acceleration, determine the tangential component of the net force exerted on the car (by the ground) when its speed is 15 m/s. Express your answer to two significant figures and include the appropriate units. HA ? Ftan = Value Units Submit Request AnswerAssuming constant tangential acceleration, determine the tangential component of the net force exerted on the car (by the ground) when its speed is 15 m/s. Express your answer to two significant figures and include the appropriate units. m R_equest Answer Part B Determine the centripetal component of the net force exerted on the car (by the ground) when its speed is 15 m/s. Express your answer to two significant figures and include the appropriate units. m Ft_equest Answer Item 11 I Review | Constant Ajet plane traveling 1840 km/h (511 111/5 ) pulls out of a dive by moving in an arc of radius 5.20 km . V PartA What is the plane's acceleration in 9's? Express your answer to three significant figures. m Muest Answer Item 12 I Review | Constants V PartA If you doubled the mass and tripled the radius of a planet, by what factor would 9 at its surface change? Express your answer using three significant figures. m Muest Answer Item 13 I Review | Constants V PartA If you swing a bucket of water fast enough in a vertical circle, at the highest point the water does not spill out. This happens because an outward force balances the pull of gravity on the water. O True O False m Quest