All categories

3 years ago

PLZ HELP ME i don’t get this

Physics

1 answer:

Scorpion4ik [409]3 years ago

4 0

Explanation:

(i) Height of tree, h = 4 m

Mass of Ninja, m = 30 kg

The gravitational potential energy on the top branch of the tree is given by :

$P=mgh$

g is acceleration due to gravity

$P=30\ kg\times 9.8\ m/s^2\times 4\ m\\\\P=1176\ J$

(ii) If he were at a height of 2 meters from the ground, its potential energy will be :

$P=mgh$

g is acceleration due to gravity

$P=30\ kg\times 9.8\ m/s^2\times 2\ m\\\\P=588\ J$

Therefore, this is the required explanation.

You might be interested in

A silver sphere with radius 1.3611 cm at 23.0°C must slip through a brass ring that has an internal radius of 1.3590 cm at the s

Readme [11.4K]

Answer:

The temperature must the ring be heated so that the sphere can just slip through is 106.165 °C.

Explanation:

For brass:

Radius = 1.3590 cm

Initial temperature = 23.0 °C

The sphere of radius 1.3611 cm must have to slip through the brass. Thus, on heating the brass must have to attain radius of 1.3611 cm

So,

Δ r = 1.3611 cm - 1.3590 cm = 0.0021 cm

The linear thermal expansion coefficient of a metal is the ratio of the change in the length per 1 degree temperature to its length.

Thermal expansion for brass = 19×10⁻⁶ °C⁻¹

Thus,

$\alpha=\frac {\Delta r}{r\times \Delta T}$

Also,

$\Delta T=T_{final}-T_{Initial}$

So,

$19\times 10^{-6}=\frac {0.0021}{1.3290\times (T_{final}-23.0)}$

Solving for final temperature as:

$(T_{final}-23.0)=\frac {0.0021}{1.3290\times 9\times 10^{-6}}$

Final temperature = 106.165 °C

5 0

3 years ago

HELPPPpPppPp!!!! !!!!!!!

matrenka [14]

Answer:

21.0

Explanation:

8 0

3 years ago

Read 2 more answers

When you see Marjorie, she is swinging a bucket of water around in a circle. The speed of the bucket of water does not change as

ser-zykov [4K]

Answer:A

Explanation:

Since the bucket of water is constantly in motion it implies a force must be acting on it which allows it to change its Position constantly.

A constant gravity Force must be acting on water . In addition to gravity force a centripetal force must be acting on the water inside the bucket.

Bucket must move with certain velocity in order to avoid spilling of water.

4 0

3 years ago

Mechanical energy that has been "lost" to friction has actually been

umka21 [38]

The answer to the question is true

5 0

3 years ago

Read 2 more answers

What does the phrase "1 meter per second per second" means? A. The velocity of an object can increase by 1 meter per second, for

OLga [1]

Explanation:

"1 meter per second per second" means acceleration of an object. It is equal to the rate of change of velocity. Its SI unit is $m/s^2$ .

It is simply given by :

$a=\dfrac{dv}{dt}$

dv is change in velocity

dt is small interval of time

"1 meter per second per second" means that the velocity of an object can increase by 1 meter per second.

4 0

3 years ago