MATH SOLVE

4 months ago

Q:
# Two kids are roller skating. Amy, with a mass of 55 kg, is traveling forward at 3 m/s. Jenny, who has a mass of 40 kg, is traveling in the opposite direction at 5 m/s. They crash into each other and hold onto each other so that they move as one mass. How fast are they traveling?

Accepted Solution

A:

Answer:

7/19 m/sec in Jenny's direction

Explanation:

Assume that the direction of motion of Amy is the default direction given the positive sign.

Therefore. Jenny's direction will be given a negative sign.

The law of conservation of momentum states that: "For a closed system, momentum is conserved.

This means that:

M1V1 + M2V2 = M3V3

where:

M1 is Amy's weight = 55 kg

V1 is Amy's velocity = 3 m/sec

M2 is Jenny's weight = 40 kg

V2 is Jenny's velovity = -5 m/sec

M3 is their final mass = 55+40 = 95 kg

V3 is their final velocity that we want to find

Substitutw with the givens in the above equation to get the final velocity as follows:

(55)(3) + (40)(-5) = 95V3

165 - 200 = 95V3

-35 = 95 V3

V3 = -7/19 m/sec

This means that their final velocity is 7/19 m/sec in Jenny's direction

Hope this helps :)

7/19 m/sec in Jenny's direction

Explanation:

Assume that the direction of motion of Amy is the default direction given the positive sign.

Therefore. Jenny's direction will be given a negative sign.

The law of conservation of momentum states that: "For a closed system, momentum is conserved.

This means that:

M1V1 + M2V2 = M3V3

where:

M1 is Amy's weight = 55 kg

V1 is Amy's velocity = 3 m/sec

M2 is Jenny's weight = 40 kg

V2 is Jenny's velovity = -5 m/sec

M3 is their final mass = 55+40 = 95 kg

V3 is their final velocity that we want to find

Substitutw with the givens in the above equation to get the final velocity as follows:

(55)(3) + (40)(-5) = 95V3

165 - 200 = 95V3

-35 = 95 V3

V3 = -7/19 m/sec

This means that their final velocity is 7/19 m/sec in Jenny's direction

Hope this helps :)