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klio [65]
3 years ago
12

A particle is moving with a velocity of 60.0 m/s in the positive x direction at t= 0. Between t= 0 and t= 15.0 s the velocity de

creases uniformly to zero. What was the acceleration during this 15.0-s interval? What is the significance of the sign of your answer?
Physics
1 answer:
Juliette [100K]3 years ago
7 0

Answer:

Acceleration of the object is given as

a = - 4 m/s^2

so here negative sign shows that the direction of acceleration is opposite to the velocity of the object

Explanation:

As we know that velocity decreases uniformly from maximum to zero

so here in this uniform deceleration we know that

v_i = 60 m/s

v_f = 0

t = 15 s

now by using the equation of kinematics we have

v_f - v_i = at

0 - 60 = a(15)

a = - 4 m/s^2

so here negative sign shows that the direction of acceleration is opposite to the velocity of the object

You might be interested in
Calculate the change in entropy that occurs in the system when 3.10 mole of isopropyl alcohol (C3H8O) melts at its melting point
ozzi

Answer:

3.10 mole of C3H8O change in entropy is 89.54 J/K

Explanation:

Given data

mole = 3.10 moles

temperature = -89.5∘C = -89 + 273 = 183.5 K

ΔH∘fus = 5.37 kJ/mol =  5.3 ×10^3 J/mol

to find out

change in entropy

solution

we know change in entropy is ΔH∘fus / melting point

put these value so we get change in entropy that is

change in entropy 5.3 ×10^3 / 183.5

change in entropy is 28.88 J/mol-K

so we say 1 mole of C3H8O change in entropy is 28.88 J/mol-K

and for the  3.10 mole of C3H8O change in entropy is 3.10 ×28.88  J/K

3.10 mole of C3H8O change in entropy is 89.54 J/K

4 0
3 years ago
Read 2 more answers
Many Amtrak trains can travel at a top speed of 42.0 m/s. Assuming a train maintains that speed for several hours, how many kilo
777dan777 [17]

Answer:

605 km

Explanation:

Hello

the same units of measure should be used, then

Step 1

convert  42 m/s ⇒   km/h

1 km =1000 m

1 h = 36000 sec

42 \frac{m}{s}*\frac{1\ km}{1000\ m}=0.042\ \frac{km}{s}\\ 0.042\ \frac{km}{s}\\

0.042\ \frac{km}{s}*\frac{3600\ s}{1\ h} =151.2 \frac{km}{h}\\ \\Velocity =151.2\ \frac{km}{h}

Step 2

find kilometers traveled after 4  hours

V=\frac{s}{t}\\ \\

V,velocity

s, distance traveled

t. time

now, isolating s

V=\frac{s}{t} \\s=V * t\\

and replacing

s=V * t\\s=151.2\frac{km}{h}*4 hours\\ s=604.8 km\\

S=604.8 Km

Have a great day

4 0
3 years ago
How much power is used in a machine that produces 15 Joules of work in 3 seconds? Use the formula P = W/t.
Marta_Voda [28]
P=w/t


w=15
t=3
therefore, 5 watts (b)
7 0
3 years ago
How much heat is released when 432 g of water cools down from 71'c to 18'c?
maria [59]
The heat released by the water when it cools down by a temperature difference \Delta T is
Q=mC_s \Delta T
where
m=432 g is the mass of the water
C_s = 4.18 J/g^{\circ}C is the specific heat capacity of water
\Delta T =71^{\circ}C-18^{\circ}C=53^{\circ} is the decrease of temperature of the water

Plugging the numbers into the equation, we find
Q=(432 g)(4.18 J/g^{\circ}C)(53^{\circ}C)=9.57 \cdot 10^4 J
and this is the amount of heat released by the water.
7 0
3 years ago
A boat with a weight of 547 newtons is floating in a harbor. What is the buoyant force on the boat?
Veronika [31]

Answer:

a

Explanation:

its correct

3 0
3 years ago
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