Question

A particle is projected vertically upward with a speed of 100 m/s. The distance travelled by the particle in first fifteen seconds is (g = 10 m/s2) A 375 m B 625 m C 750 m D 500 m​

Answer 1

u = 100 m/s

t = 15 s

g = - 10 m/s²

We know,

S = ut + 1/2 at²

=> S = (100 m/s)(15 s) + 1/2 (- 10 m/s²)(15 s)²

=> S = 1500 m - 1125 m

=> S = 375 m (A).

Answer 2

Answer:

B. 625 ✔️

Step-by-step explanation:

Given:

• A particle is projected vertically upward.
• Speed of a particle = 100 m/s
• g = 10 m/s²

To find:

• The distance travelled by the particle in first fifteen seconds.

Solution:

We know that,

• Time to reach maximum height, t = u/g
• Time to reach maximum height, t = 100/10
• Time to reach maximum height, t = 10 s

Finally,

• Distance = u²/2g + 1/2 gt²
• Distance = 100²/(2 × 10) + 1/2 × 10 × 5²
• Distance = 100²/20 + 5 × 5²
• Distance = 100²/20 + 5 × 25
• Distance = 10000/20 + 5 × 25
• Distance = 1000/2 + 5 × 25
• Distance = 500 + 5 × 25
• Distance = 500 + 125
• Distance = 625 m

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