A 50 kg skater at rest on a frictionless rink throws a 2 kg ball, giving the ball a velocity of 10 m/s. Which statement describes the skaters subsequent motion? Explain please.
a. 0.4 m/s in the same direction as the ball.
b. 0.4 m/s in the opposite direction of the ball.
c. 2 m/s in the same direction as the ball.
d. 4 m/s in the same direction as the ball.
e. 4 m/s in the opposite direction of the ball
4 answers
(b)0.4m/s in the opposite direction of the ball.
How..??
Please explain how,?????...??
When using the equation for conservation of momentum (Pinitial=Pfinal), the equation should always be set up like this: m1v1i-m2v2i=m1v1f-m2v2f). Since both objects are initially at rest, the left side of the equation is equal to zero. m1 represent the mass of the skater and v1f represent their final velocity (which you're solving for). Plug in the mass and the velocity of the ball for m2 and v2f and solve for v1f.
Steps:
0=m1v1f-m2v2f
0=(50kg)(v1f)-(2kg)(10m/s)
v1f=.4m/s
Steps:
0=m1v1f-m2v2f
0=(50kg)(v1f)-(2kg)(10m/s)
v1f=.4m/s
5 answers