During photosynthesis, energy from sunlight is used to start a reaction with blank

A 4 kg object is moving at a speed of 5 m/sec. How much kinetic energy does the object have? A. 10 joules B. 20 joules C. 50 jou

sp2606 [1]

Answer:

A. 10 joules

Explanation:

Given parameters:

Mass of object = 4kg

Speed = 5m/s

Unknown:

Kinetic energy of the the object = ?

Solution:

Kinetic energy is the energy due to a moving body.

So;

mathematically;

K.E = $\frac{1}{2}$ x m v²

m is the mass

v is the velocity

K.E = $\frac{1}{2}$ x 4 x 5 = 10J

5 0

3 years ago

A ball dropped from a height of 50 meters, Determine the speed of the ball after 3 seconds

Alex17521 [72]

16.7 m/s

To determine the speed we use the formula: Distance ÷ Time so, 50 ÷ 3 = 16.66... ( rounded off to 1.d.p is 16.7).

8 0

4 years ago

A rocket sled accelerates at a rate of 49.0 m/s2 . Its passenger has a mass of 75.0 kg. (a) Calculate the horizontal component o

Katen [24]

Explanation:

It is given that,

Mass of the passenger, m = 75 kg

Acceleration of the rocket, $a=49\ m/s^2$

(a) The horizontal component of the force the seat exerts against his body is given by using Newton's second law of motion as :

F = m a

$F=75\ kg\times 49\ m/s^2$

F = 3675 N

Ratio, $R=\dfrac{F}{W}$

$R=\dfrac{3675}{75\times 9.8}=5$

So, the ratio between the horizontal force and the weight is 5 : 1.

(b) The magnitude of total force the seat exerts against his body is F' i.e.

$F'=\sqrt{F^2+W^2}$

$F'=\sqrt{(3675)^2+(75\times 9.8)^2}$

F' = 3747.7 N

The direction of force is calculated as :

$\theta=tan^{-1}(\dfrac{W}{F})$

$\theta=tan^{-1}(\dfrac{1}{5})$

$\theta=11.3^{\circ}$

Hence, this is the required solution.

8 0

4 years ago

What is the specific heat of a substance that absorbs 2500 joules of heat when a sample of 1.200 kg of the substance increases i

Anarel [89]

Answer:

0.035 J/g°C

Explanation:

From the question given above, the following data were obtained:

Heat (Q) absorbed = 2500 J

Mass (M) = 1.2 Kg

Initial Temperature (T₁) = 10 °C

Final Temperature (T₂) = 70 °C

Specific heat capacity (C) =?

Next, we shall determine the change in temperature. This can be obtained as follow:

Initial Temperature (T₁) = 10 °C

Final Temperature (T₂) = 70 °C

Change in temperature (ΔT) =

ΔT = T₂ – T₁

ΔT = 70 – 10

ΔT = 60 °C

Thus, the change in the temperature of the substance is 60 °C

Next, we shall convert 1.2 Kg to grams (g). This can be obtained as follow:

1 Kg = 1000 g

Therefore,

1.2 Kg = 1.2 Kg × 1000 g / 1 Kg

1.2 Kg = 1200 g

Thus, 1.2 Kg is equivalent to 1200 g.

Finally, we shall determine the specific heat capacity of substance. This can be obtained as follow:

Heat (Q) absorbed = 2500 J

Mass (M) = 1200 g

Change in temperature (ΔT) = 60 °C

Specific heat capacity (C) =?

Q = MCΔT

2500 = 1200 × C × 60

2500 = 72000 × C

Divide both side by 72000

C = 2500 / 72000

C = 0.035 J/g°C

Therefore, the specific heat capacity of the substance is 0.035 J/g°C

3 0

3 years ago

Which statement is true about the speed of heat transfer by conduction?

antiseptic1488 [7]

Answer:

Conduction is fastest in solid

Explanation:

A basic property of conduction is that for heat to transfer there must be contact. From kinetic theory, configuration of solid is such that the molecules are held together and they move or vibrate about their mean position. Because of this arrangement heat transfer by conduction is faster in solid that any other state of matter

3 0

3 years ago