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Norma-Jean [14]
3 years ago
7

Need help with both questions!

Physics
1 answer:
xenn [34]3 years ago
7 0
#14 isn't really a Physics problem.  It's more of just reading a graph.

A). When speed changes, acceleration is

       (change in speed) / (time for the change) .

To be correct about it, acceleration can be positive ... when speed
is increasing ... or it can be negative ... when speed is decreasing.
So, on this graph, there are two periods of acceleration:

From zero to 2 seconds, acceleration = (8 m/s) / (4 sec) = 2 m/s² .

From 10 to 12 seconds, acceleration = (-4 m/s) / (2 sec) = -2 m/s² .

B). From 12 to16 seconds, you can read the speed right from
the graph.  It's 4 m/s .

C).  From 2 to 10 seconds, the objects speed is a steady 8 m/s.
Covering 8 m/s every second for 8 seconds, it covers 64 meters.
Do you remember that distance is the area under the speed/time
graph?  You can see that plainly on this graph.  From 2 to 10 sec,
there are 16 blocks.  Each block is (2 m/s) high and (2 sec) wide,
so its area is (2 m/s) x (2 sec) = 4 meters.  The area of 16 blocks
is (16) x (4 meters) = 64 meters.
====================================

#15.

a).  constant velocity on a distance graph is a line that slopes up;
constant velocity on a velocity graph is a horizontal line;

b). positive constant acceleration on a distance graph is a
line that curves up;
positive constant acceleration on a velocity graph is a
straight line that slopes up;

c).  "uniformly slowing down to a stop" on a distance graph
is a line that's less and less curved as time goes on, and
eventually reaches the x-axis.
"uniformly slowing down to a stop" on a velocity graph is
a straight line that slopes down, and stops when it reaches
the x-axis.




You might be interested in
A 34n force is applied to a 213kg mass how much does the mass accelerate
motikmotik
We Know, F = m*a
Here, F = 34 N
m = 213 Kg

Substitute their values in the equation,
34 = 213 * a
a = 34/213
a = 0.159 m/s²

So, your final answer & the acceleration of the object would be 0.159 m/s²

Hope this helps!
3 0
3 years ago
Radar is used to determine distances to various objects by measuring the round-trip time for an echo from the object. (a) How fa
zloy xaker [14]

Answer:

150000000000 m

0.0000005 seconds

33.33 ns

Explanation:

Speed of electromagnetic waves through vacuum = 3\times 10^8\ m/s

Echo time = 1000 seconds

Echo time is the time taken to reach the object and come back to the observer

Distance = Speed×Time

Distance=3\times 10^8\times \frac{1000}{2}=150000000000\ m

Venus is 150000000000 m away from Earth

Time = Distance / Speed

Time=\frac{75}{3\times 10^8}=0.00000025\ seconds

Echo time will be twice the time

Echo\ time=2\times 0.00000025=0.0000005\ seconds

The echo time will be 0.0000005 seconds

Difference in time = Difference in distance / Speed

\Delta t=\frac{\Delta d}{v}\\\Rightarrow \Delta t=\frac{10}{3\times 10^8}\\\Rightarrow \Delta=33.33\ ns

The accuracy by which I will be able to measure the echo time is 33.33 ns

5 0
3 years ago
How do two objects at different temperatures attain thermal equilibrium?
Lady bird [3.3K]

Answer:

C.As the two objects touch, thermal energy flows as heat from the warmer block to the colder block until particles in both blocks move at the same rate and reach the same temperature.

Explanation:

Heat is the transfer of thermal energy from an object at higher temperature to an object at colder temperature.

The temperature of an object is a measure of how fast the particles in the object move: the higher its temperature, the faster the particles move, the higher the average kinetic energy of the particles in the object. As a result, the particles of the object at higher temperature tend to transfer more energy (called thermal energy) to the particles of the object at colder temperature by colliding with them: this process continues until the particles of the colder object reach the same average kinetic energy as the particles of the warmer object, and this means that the two objects have reached the same temperature.

3 0
3 years ago
A vase of flowers is stationary on a table. which of the following statements best explains why the vase is stationary?
goldenfox [79]
D. The table pushes up on the vase with the same amount of force as gravity pulling it down.
7 0
3 years ago
An object falls from a high building and hits the ground in 8.0 seconds. Ignoring air resistance, what is the distance that it f
d1i1m1o1n [39]

Answer:

310 meters

Explanation:

Given:

v₀ = 0 m/s

t = 8.0 s

a = -9.8 m/s²

Find: Δy

Δy = v₀ t + ½ at²

Δy = (0 m/s) (8.0 s) + ½ (-9.8 m/s²) (8.0 s)²

Δy = -313.6

Rounded to two significant figures, the object fell 310 meters.

4 0
3 years ago
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