Answer:
20
Step-by-step explanation:
Speed is 10 m/s
Kinetic energy is 1000joules
Mass is ?
Therefore the mass can be calculated as follows
K.E= 1/2mv^2
1000= 1/2 × m × 10^2
1000= 1/2 × m × 100
1000= 100m/2
2000= 100m
m= 2000/100
m= 20
Hence the mass is 20kg