Question

A man throws a mass of 2 kg vertically upwards with a velocity of 20m /sec.What is the p.e. of mass after 1 sec??

Answer 1

Since,

h= ut - 1/2*g*t^2 (in case of upward motion)

=) h = 20*1 - 0.5* 10*1*1 ( take g = 10)

=) h = 20 - 5

=) h = 15m.

Hence Pe = meh

= 2*10*15 J

= 300J.

Hope it's helpful to u.

Answer 2

Q. A man throws a mass of 2 kg vertically upwards with a velocity of 20m /sec.What is the p.e. of mass after 1 sec??

$\huge{\underline{\tt{\red{Solution-}}}}$

$\longrightarrow \sf{Using: s = ut+\dfrac{1}{2}}{at}^{2}$

$\longrightarrow \sf{Using: s = 20\times1+\dfrac{1}{2}}{(-10)1}^{2}$

$\small\implies{\sf{\blue15 m}}$

Potential energy = mgh = ${2\times10\times15}$

$\small\implies{\sf{\blue 300 J}}$