Ask question

Ask question

All categories

lisabon 2012 [21]

3 years ago

9

Please help me................

1 answer:

Vikentia [17]3 years ago

3 0

Answer:

4

Explanation:

Cause it literally says

You might be interested in

Planet-solar system-galaxy-local group. what comes next

Lubov Fominskaja [6]

Answer:

Super cluster

Explanation:

3 0

3 years ago

A school bus moves past a parked car at a speed of 30 km/hr. Which of the following BEST describes the observation made by a pas

ddd [48]

Answer:

C.The car appears to be moving 30 km/hr in the opposite direction of the bus.

Explanation:

There are two reference systems involved in this situation:

- Reference system S: this is the reference system where velocities are measured with respect to the ground. In this reference system, the car is parked, so its velocity is $v=0$

- Reference system S': this is the reference system moving with the bus. This reference system is moving with a velocity of $v_0 = +30 km/h$ with respect to the reference system S

Calling $v'$ the velocity of the car in the reference system S', we have:

$v=v_0 +v'$

From which

$v'=v-v_0 = 0-(+30 km/h)=-30 km/h$

and the negative sign means that a passanger in the bus observes the car moving in the opposite direction.

8 0

4 years ago

A 0.250 kg block on a vertical spring with spring constant of 4.45 ✕ 103 N/m is pushed downward, compressing the spring 0.080 m.

Elza [17]

Answer:h=5.81 m

Explanation:

Given

Mass of block(m)=0.250 kg

Spring Constant $k=4.45\times 10^3 N/m$

Initial elongation =0.080 m=8 cm

Thus Initial Potential Energy stored =Final Potential Energy stored in Block

$P_i=\frac{kx^2}{2}$

$P_i=\frac{4.45\times 10^3\times 64\times 10^{-4}}{2}=14.24 J$

$P_f=mgh=0.25\times 9.8\times h$

$P_i=P_f$

$14.24 =0.25\times 9.8\times h$

$h=\frac{14.24}{0.25\times 9.8}=5.81 m$

6 0

3 years ago

A 2,000 kg car is moving at 15m/s when it collides with a 1200kg car sitting still. Briefly compare the impulse imparted on the

I am Lyosha [343]

impulse = F × t

The greater the impulse exerted on something, the greater will be the change in momentum.

impulse = change in momentum

Ft = ∆(mv)

4 0

4 years ago

Read 2 more answers

How do i find stretch? The problem in questioning has already given me the elastic energy and k-value, but I have no idea how to

finlep [7]

Answer:

Stretch can be obtained using the Elastic potential energy formula.

The expression to find the stretch (x) is $x=\sqrt{\frac{2\times EPE}{k}}$

Explanation:

Given:

Elastic potential energy (EPE) of the spring mass system and the spring constant (k) are given.

To find: Elongation in the spring (x).

We can find the elongation or stretch of the spring using the formula for Elastic Potential Energy (EPE).

The formula to find EPE is given as:

$EPE=\frac{1}{2}kx^2$

Rewriting the above expression in terms of 'x', we get:

$x=\sqrt{\frac{2\times EPE}{k}}$

Example:

If EPE = 100 J and spring constant, k = 2 N/m.

Elongation or stretch is given as:

$x=\sqrt{\frac{2\times EPE}{k}}\\\\x=\sqrt{\frac{2\times 100}{2}}\\\\x=\sqrt{100}=10\ m$

Therefore, the stretch in the spring is 10 m.

So, stretch in the spring can be calculated using the formula for Elastic Potential Energy.

6 0

3 years ago