) A car is moving at 20 m/s. When the driver applies the brakes, the car travels
ID: 777693 • Letter: #
Question
) A car is moving at 20 m/s. When the driver applies the brakes, the car travels 120 m before coming to rest. a. Find its acceleration (or deceleration). b. Compute the time taken for the car to stop. 2 A box of mass 10 kg rests on a rough horizontal surface. A force of 120 N pulls on a. Draw a neat diagram showing all the forces, horizontal and vertical, acting on the b. What is the acceleration of the box? In which direction? it to the right, while two forces: 50 N and 80 N pull it to the left. box A football player is 6' 6" tall and weighs 320 lbs. Convert to his height and weight into meters and kilograms. 4.) A man stands on the top of a 98 m high building and throws down a stone at a a. b. speed of 10 m/s What is the speed of the stone just as it strikes the ground? How long did it take to reach the ground? A 100g stone tied to a string 150 cm long rotates in a horizontal circle with a period of 0.5 second. Calculate: a. The speed of the stone. b. The centripetal force. A 1.2 tonne sports car is moving at 108 km/hr when the driver sees traffic ahead and applies the brakes to slow the car down to 36 km/hr. Compute the change in the car's kinetic energy. 6. 7.) A 300 kg piano is lifted by a crane to the 4th floor of an apartment building, 15 m ground level. If the crane took 30 seconds to lift the piano, calculate: above the change in potential energy of the piano. the power generated by the crane's engine. a. b.Explanation / Answer
1)initial speed of car=20 m/s
ditsnace travelled before coming to rest =120 m
let the acceleration be a
v2=u2+2as
02=202+(2*a*120)
a=-1.67 m/s2
b) time taken for the car to stop=20/1.67=12 seconds
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.