Question

How fast should a man weighing 600 N run so that his kinetic energy is 750 J?
(g = 10 ms-²)​

Answer 1

Answer:

Explanation:

K.E = 1/2mv²

K.E = 750 J, W = 600 N, g = 10

We know that W = mg. So m = W/g = 600 / 10 = 60 Kg

Then from K.E = 1/2mv²

750 = 1/2 x 60 x v²

750 x 2 60 x v²

1500 = 60 x v²

v² = 1500 / 60 = 25

v = √25 = 5 m/s²

Hope this helps.

Answer 2

Question:

• How fast should a man weighing 600 N run so that his kinetic energy is 750 J?
• (g = 10 ms-²)

Information provided with us:

• Weight of a man is 600 N
• Kinetic energy is 750 J
• g is 10 ms-²

What we have to calculate:

• We have to find out the velocity at which that man was running.

Finding out the mass:-

Using Formula,

• W = mg

Here W is work done , m is mass and g is 10.

→ 600 = m(10)

→ 600 = m × 10

→ m = 600/10

→ m = 60 kg

Finding out velocity:-

Using Formula:

• K.E. = 1/2 mv²

Here,

• K.E. is kinetic energy
• m is mass
• v is velocity

We have that,

• m is 60 kg
• K.E. is 750 J

Substituting the values:

→ 750 = 1/2 (60) (v²)

→ 750 = 1/2 × 60 × v²

→ 750 = 60/2 × v²

• Dividing 60 by 2 we gets 30,

→ 750 = 30 × v²

• On transposing sides,

→ v² = 750/30

→ v² = 75/3

• On dividing 75 by 3 we gets 25,

→ v² = 25

→ v = √25

→ v = 5

• Hence, man should run at 5ms-¹ so that his kinetic energy is 750 J.