- #1

Istiak

- 158

- 12

- Homework Statement
- A stuntman jumped from $1.25 \ \text{m}$ height and, landed at distance $10 \ \text{m}$. Find velocity when he jumped. (Take $\text{g}=10 \ ms^{-2}$)

- Relevant Equations
- $$h=\frac{1}{2}gt^2$$

>

>A stuntman jumped from $1.25 \ \text{m}$ height and, landed at distance $10 \ \text{m}$. Find velocity when he jumped. (Take $\text{g}=10 \ ms^{-2}$)

I had solved it following way.

$$h=\frac{1}{2}gt^2$$

$$=>1.25=5\cdot t^2$$

$$=>t=\frac{1}{2}$$

And, $$s=vt$$

$$v=\frac{s}{t}$$

$$=\frac{10 \ m}{\frac{1}{2} \ s}$$

$$=20 \ m/s$$

The answer is correct (checked from book answer). But, $v$ is average speed in the following equation.

$$s=vt$$

But, they told me to find initial velocity. That's why I think my answer is correct but, method is wrong so, the whole work is wrong either.

>A stuntman jumped from $1.25 \ \text{m}$ height and, landed at distance $10 \ \text{m}$. Find velocity when he jumped. (Take $\text{g}=10 \ ms^{-2}$)

I had solved it following way.

$$h=\frac{1}{2}gt^2$$

$$=>1.25=5\cdot t^2$$

$$=>t=\frac{1}{2}$$

And, $$s=vt$$

$$v=\frac{s}{t}$$

$$=\frac{10 \ m}{\frac{1}{2} \ s}$$

$$=20 \ m/s$$

The answer is correct (checked from book answer). But, $v$ is average speed in the following equation.

$$s=vt$$

But, they told me to find initial velocity. That's why I think my answer is correct but, method is wrong so, the whole work is wrong either.