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3 years ago

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Physics

1 answer:

katen-ka-za [31]3 years ago

3 0

Answer:

C. 2 and 4

Explanation:

my teacher went over it and the answer was that

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A 4000-kg car bumps into a stationary 6000kg truck. The Velocity of the car before the collision was +4m/s and -1m/s after the c

Goryan [66]

Answer:

The velocity of the truck is 3.33 m/s

Explanation:

Law Of Conservation Of Linear Momentum

The total momentum of a system of bodies is conserved unless an external force is applied to it. The formula for the momentum of a body with mass m and velocity v is

P=mv.

If we have a system of bodies, then the total momentum is the sum of the individual momentums:

$P=m_1v_1+m_2v_2+...+m_nv_n$

If some collision occurs, the velocities change to v' and the final momentum is:

$P'=m_1v'_1+m_2v'_2+...+m_nv'_n$

In a system of two masses:

$m_1v_1+m_2v_2=m_1v'_1+m_2v'_2$

There are two objects: The m1=4000 Kg car and the m2=6000 Kg truck. The car was moving initially at v1=4 m/s and the truck was at rest v2=0. After the collision, the car moves at v1'=-1 m/s. We need to find the velocity of the truck v2'. Solving for v2':

$\displaystyle v'_2=\frac{m_1v_1+m_2v_2-m_1v'_1}{m_2}$

Substituting:

$\displaystyle v'_2=\frac{4000*4+6000*0-4000(-1)}{6000}$

$\displaystyle v'_2=\frac{16000+4000}{6000}$

$\displaystyle v'_2=3.33$

The velocity of the truck is 3.33 m/s

7 0

3 years ago

A student drops a 0.4kg ball from a height a of 49m above the ground. Neglect drag. Answer each of the following questions about

Elan Coil [88]

• The only force acting on the ball, and thus the net force, is due to its own weight, with magnitude

w = m g = (0.4 kg) (9.8 m/s²) ≈ 3.9 N

pointing downward.

• The ball is in free fall, so its acceleration is g = 9.8 m/s² (also pointing downward).

• The ball is dropped from a height of 49 m, so its height y at time t is

y = 49 m - 1/2 g t ²

Set y = 0 and solve for t :

0 = 49 m - 1/2 g t ²

t ² = (98 m) / g

t = √((98 m) / g) = √(10) s ≈ 3.2 s

• The ball's velocity v at time t is

v = - g t

so that at the time found previously, the ball will have attained a velocity of

v = - g (3.2 s) ≈ -31 m/s

and thus a speed of about 31 m/s.

4 0

3 years ago

A car is sitting still. It accelerates to a constant speed then it decelerates again to zero speed. While the car is acceleratin

Kobotan [32]

Answer:

in the acceleration process the quantity α and w must increase

the deceleration process the alpha quantity must constant a direction opposite to the angular velocity

Explanation:

Acceleration and angular velocity are related to linear

v = w xr

a = αx r

The bold letters indicate vectors and the cross is a vector product, therefore if

we can see that the relationship between linear and angular variables is direct

therefore in the acceleration process the quantity α and w must increase as well as their linear counterparts

in the deceleration process the alpha quantity must constant as the linear acceleration and must have a direction opposite to the angular velocity

5 0

3 years ago

how does the pattern of heat transfer from Earth’s interior to Earth’s surface affect the Earth’s plates?

olga_2 [115]

Answer:

that it is bumpy or by the sun

Explanation:

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3 years ago

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To develop a product that warms peoples hands would you use an exothermic or endothermic reaction? Why?

il63 [147K]

Exothermic because exothermic reactions transfer energy to the surroundings. Endothermic reactions take in energy from the surroundings, so if you want to warms people's hands you should use exothermic chemical reaction for the product.

4 0

3 years ago

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