5 points The figure below shows two people ice-skating. Person A collides with
person B. After the collision they move together with the same velocity.
Calculate the mass, m, of person B.

Before collision
After collision
Person A
mass = 60 kg
Person B
mass, m
Person A and person B
moving off together
Speed of
Person A -
5.5 m/s
Speed of
Person B -
2.0 m/s
Speed of Person A and
Person B = 4.0 m/s

mB = 45 kg

Explanation:

Using conservation of linear momentum,

mAvA + mbvB = (mA + mB)v

(60 kg)(5.5 m/s) + (2.0 m/s)mB = (60 kg + mB)(4.0 m/s)

(330) + 2mB = 240 + 4mB

2mB = 90

mB = 45 kg

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.