A machine has an efficiency of 20 percent. Find the input work if the output work is 140 Joules

Answer:

10000    

Explanation:

When shifting the decimal point left, the number effectively gets divided by 10 for each movement.

Conversely, shifting it to the right corresponds to multiplying the number by 10 for every unit moved.

If the decimal point is moved four units to the left, it becomes 0.0003, which is equivalent to dividing 3.0 by 10000

Answer:

A) denotes the resultant velocity of cart B post-collision.

B)

C)

D)

E)

F) Yes, kinetic energy remains conserved in this situation because both colliding bodies have identical mass.

G) Yes, momentum is conserved in every elastic collision.

Explanation:

Given:

• mass of car A,

• mass of car B,

• initial velocity of car A,

• final velocity of car A,

A)

The question mentions the cars experience an elastic collision:

By applying momentum conservation principles:

denotes the resulting velocity of cart B after collision.

B)

Initial kinetic energy of cart A:

C)

Initial kinetic energy of cart A:

D)

The final kinetic energy of cart A:

E)

The final kinetic energy of cart B:

F)

Yes, kinetic energy is conserved in this case due to both masses being identical in the collision.

G)

Indeed, momentum is consistently conserved in elastic collisions.

Answer:

Statements 4, 6 & 7 are incorrect.

Explanation:

In any elastic collision, the overall momentum vector sum of the system remains zero.

In this scenario, an elastic collision occurs between the ball and a stationary wall. The ball's velocity will consistently revert after the impact, leading to a change in direction of momentum.

The initial momentum of the ball is represented as:

where:

m = mass of the ball

v = initial velocity of the body

post-collision for the elastic interaction:

• Here, the momentum changes solely in direction, thus contradicting statement 7.

• During the impact, both the ball and the wall exert forces on each other that are equal and opposite. The wall remains motionless, while the ball is influenced by the wall's reaction force, performing work on it, which contradicts statement 4.

• Given that this collision is elastic, the ball's form and dimensions do not alter.

• The previous points clearly indicate that not all provided statements hold true, thus violating statement 6.

When helium is released from a compressed container, the decompressed atoms expand and rise, causing the rubber balloon to inflate and float along. In this scenario, helium exists in a gaseous state.

(B) (length)/(time³) Explanation: The term x = ½ at² + bt³ should meet dimensional consistency. This means that both bt³ and ½ at² must share the same units, which are length. To find the dimension of b, we rearrange the equation: [x] = [b]*[t]³ leads to length = [b]*time³, hence [b] = length/time³.