Answer:
945 j
Explanation:
You have just given the ball kinetic energy, which is given by the following equation:
KE= 1⁄2 m v2 = 1⁄2 (2.1 kg)(30 m/s)2 = 945 Joules
Weight is different (but mass is the same)
Answer:
mass = 4kg
Explanation:
Kinetic Energy = 1/2 x m x v²
where m = mass and v = velocity
So,
KE = 50
1/2 × m × 5² = 50
1/2 × m × 25 = 50
m = (50 x 2)/25
m = 100/25
m = 4 kg