Question

if you want to go on an air - plane speed of 5.5 km/h and need to travel a total distance of 333 km, how long will it take to reach the destination?
49.
a. 300 hours
b. 30 hours
c. 22.2 hours
d. 60.5 hours

1. velocity and time information for a car moving are as shown. what is the magnitude of acceleration of the car?

v_i = 4.0 m/s, v_f = 18.0 m/s, t = 4.0 s
a. 4 m/s²
b. 3.5 m/s²
c. 6 m/s²
d. 3 m/s²

1. an object with a mass of 17.8 g is accelerated uniformly at 3.6 m/s². what force is required to do so?

a. 9.95 n
b. 2.3 n
c. 20.8 n
d. 57.0 n

1. what is the mass of an object if a force of 0.248 n allows it to accelerate at 37 m/s²?

a. 0.0106 kg
b. 0.0106 n
c. 1365 kg
d. 9.04 kg
for questions 51 - 52, use the atom diagram below.

1. which letter in the atom diagram points to a neutron?

a. a
b. b
c. c
d. d

1. which letter in the above diagram points to an electron?

a. a
b. b
c. c
d. d

Explanation:

Question 47

Step1: List given values

Initial velocity $u = 5.2\ \text{km/h}$, final velocity $v = 0$, distance $s = 1\ \text{km}$

Step2: Convert units to standard form

$u = 5.2 \times \frac{1000}{3600} \approx 1.444\ \text{m/s}$, $s = 1000\ \text{m}$

Step3: Use kinematic equation $v^2=u^2+2as$

Rearrange for acceleration: $a = \frac{v^2 - u^2}{2s}$

Step4: Substitute values

$a = \frac{0 - (1.444)^2}{2 \times 1000} \approx \frac{-2.085}{2000} \approx -0.00104\ \text{m/s}^2$
Convert back to $\text{km/h}^2$:
$a = -0.00104 \times (3.6)^2 \times 1000 \approx -13.5\ \text{km/h}^2$
The magnitude is $13.5\ \text{km/h}^2$

Step1: List given values

Initial velocity $u = 380\ \text{m/s}$, final velocity $v = 0$, time $t = 2.4\ \text{s}$

Step2: Use acceleration formula $a=\frac{v-u}{t}$

Substitute values: $a = \frac{0 - 380}{2.4}$

Step3: Calculate acceleration

$a \approx -158.33\ \text{m/s}^2$, magnitude is $158\ \text{m/s}^2$

Step1: List given values

Initial velocity $u = 4.0\ \text{m/s}$, final velocity $v = 16.0\ \text{m/s}$, time $t = 4.0\ \text{s}$

Step2: Use acceleration formula $a=\frac{v-u}{t}$

Substitute values: $a = \frac{16.0 - 4.0}{4.0}$

Step3: Compute acceleration

$a = \frac{12.0}{4.0} = 3.0\ \text{m/s}^2$

Answer:

b. 13.5 km/h²

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Question 48