♥ C) 94%
♥ If the work put into a lever is 930 joules and the work accomplished is 870 joules, the efficiency of the lever is 94%.
♥ <span>870/930=93.5
</span>♥ And rounded you get 94.
Answer: The ball (option A)
Explanation: change in momentum is defined by the formulae m(v - u) where m = mass of object, v = final velocity and u = initial velocity.
For the ball, it hits the ground and bounces back with the same speed, that's final velocity equals initials (v = - u)
Change in momentum = m( -u- u) = m(-2u) = m(-2u) = -2mu
For the clay, it final velocity is zero since it sticks to the floor, hence (v =0)
m(v - u) = m(0 - u) = - mu.
-2mu (change in momentum from the ball) is greater than - mu ( change in momentum of clay)
Answer:
66.26 m/s
Explanation:
Horizontal velocity, Vx = 55.3 m/s
Vertical velocity, Vy = 36.5 m/s
The value of the resultant velocity is given by the vector sum of the two velocities which are acting at 90°.
V = 66.26 m/s
Thus, the velocity of the vehicle is 66.26 m/s along its descent path.
