All categories

2 years ago

A car with a mass of 1400kg is being driven along the motorway at 30m/s. Calculate the kinetic energy of the car

Physics

1 answer:

Umnica [9.8K]2 years ago

3 0

Answer:

$6.3 \cdot 10^5 J$

Explanation:

The kinetic energy of an object is given by

$K=\frac{1}{2}mv^2$

where

m is the mass of the object

v is its speed

For the car in this problem,

m = 1400 kg

v = 30 m/s

Therefore, the kinetic energy of the car is

$K=\frac{1}{2}(1400)(30)^2=6.3 \cdot 10^5 J$

You might be interested in

What is the threshold frequency for sodium metal if a photon with frequency 6.66 × 1014 s−1 ejects a photon with 7.74 × 10−20 J

FrozenT [24]

Answer:

5.5 × 10^14 Hz or s^-1

no orange light has less frequency so no photoelectric effect

Explanation:

hf = hf0 + K.E

HERE h is Planck 's constant having value 6.63 × 10 ^-34 J s

f is frequency of incident photon and f0 is threshold frequency

hf0 = hf- k.E

6.63 × 10 ^-34 × f0 = 6.63 × 10 ^-34× 6.66 × 10^14 - 7.74× 10^-20

6.63 × 10 ^-34 × f0 = 3.64158×10^-19

f0 = 3.64158×10^-19/ 6.63 × 10 ^-34

f0 = 5.4925 × 10^14

f0 =5.5 × 10^14 Hz or s^-1

frequency of orange light is 4.82 × 10^14 Hz which is less than threshold frequency hence photo electric effect will not be observed for orange light

8 0

2 years ago

Which of the following substances will show the smallest change in temperature when equal amounts of energy are absorbed?

SSSSS [86.1K]

It would be water because if you freeze it than you will still be able to see it and if you boil it than you will be able to see it disappear.

3 0

2 years ago

Read 2 more answers

the steel bed of a suspension bridge is 200m long at 20 C. If the extremes of temperature to which it might be exposed are -30 C

raketka [301]

Answer:

The steel bed will contract by 0.13 m, and expand by 0.052 m

Explanation:

For contraction,

α = ΔL/(LΔθ)..................... Equation 1

Where α = Linear expansivity of steel, ΔL = decrease in length/ Increase in length, L = Original length, Δθ = Change in temperature

make ΔL the subject of the equation

ΔL = α(LΔθ)................. Equation 2

Given: α = 13×10⁻⁶/C, L = 200 m, Δθ = -30-20 = -50 °C

Substitute into equation 2

ΔL = 13×10⁻⁶(200)(-50)

ΔL = -0.13 m

Similarly, For expansion,

Using equation 2

ΔL = α(LΔθ)

Given: α = 13×10⁻⁶/C, L = 200 m, Δθ = 40-20 = 20 °C

Substitute into equation 2

ΔL = 13×10⁻⁶(200)(20)

ΔL = 0.052 m.

Hence the steel bed will contract by 0.13 m, and expand by 0.052 m

3 0

2 years ago

What is the Physics Primer?

Elza [17]

Answer:

A. a set of mathematically topics that are relevant to introductory physics.

Explanation:

The physics primer is not defined as the online comprehensive mathematics textbooks. It is the set of topics of mathematics which gives students trouble and remember.

Therefore, it is defined as the process of physics problem solving. So, mathematically skills are covered in physics course as a primer related success.

Therefore, it is a set of topics of mathematics that are relevent to introductory physics.

7 0

2 years ago

Read 2 more answers

A Porsche 944 Turbo has a rated engine power of 217hp . 30% of the power is lost in the drive train, and 70% reaches the wheels.

scZoUnD [109]

Explanation:

(a) It is given that two-third of weight is over the drive wheels. So, mathematically, w = $\frac{2}{3}mg$ .